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Guam Taxes: What You Need to Know

Guam follows a tax system closely aligned with the U.S. federal tax code, using the same income tax brackets and rates.

Residents file their taxes with the Guam Department of Revenue and Taxation, and most federal deductions and credits apply. Additionally, Guam imposes local taxes like the Business Privilege Tax (BPT) — historically called the Gross Receipts Tax (GRT) — on businesses operating within the territory.

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Federal Tax Withholding in Guam

Guam follows the U.S. Internal Revenue Code for tax purposes. Federal income tax is withheld based on progressive tax rates — for 2026, rates range from 10% to 37%, with the exact rate depending on taxable income and filing status.

Residents of Guam have specific filing requirements. They file federal tax returns with either the Guam Department of Revenue and Taxation (DRT) or the IRS, with the choice depending on where their tax liability falls. If physically present in Guam for the entire year, they file locally.

The W-4 Form is crucial — it determines the withholding amount based on the number of allowances claimed.

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Territorial Tax Withholding

Guam, as a U.S. territory, has its own tax collection system that mirrors the U.S. federal system. It is managed through the Guam Department of Revenue and Taxation.

Guam Territorial Income Tax is withheld by employers, and tax rates mirror the U.S. federal income tax brackets. Residents pay taxes at the same rates as federal taxes, but to the Guam DRT.

The withholding process uses a Guam-specific form called Form GU-4. Like the U.S. mainland, withholding is based on income level and number of allowances.

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FICA and Insurance Taxes

FICA taxes are mandatory in Guam and are split into two parts:

Social Security Tax: Employees pay 6.2% of their income on wages up to $184,500 in 2026. (Source)

Medicare Tax: Employees contribute 1.45% of all wages. An additional 0.9% Medicare surtax applies for high earners — singles earning more than $200,000 and married couples filing jointly earning more than $250,000. (Source)

Employers match these contributions — they pay an equal share of both Social Security and Medicare taxes.

Guam-Specific Taxes

Guam participates in federally mandated programs, including Unemployment Insurance (UI).

Employers, not employees, pay unemployment taxes. These taxes fund unemployment benefits in Guam and may indirectly impact overall compensation.

Pre-Tax Deductions in Guam

Pre-tax deductions reduce taxable income, lowering withheld taxes. Common pre-tax deductions include:

Medical Insurance: Premiums for employer-sponsored health insurance can typically be deducted pre-tax. This reduces taxable income for both federal and Guam taxes.

Retirement Plans (401(k) or 403(b)): Contributions are taken out pre-tax and reduce income subject to both federal and territorial income tax. For 2026, employees can contribute up to $24,500. Those aged 50 or older can contribute an additional $8,000 as a catch-up contribution, while those aged 60–63 can contribute an enhanced $11,250 catch-up under SECURE 2.0. (Source)

Flexible Spending Accounts (FSA): If offered by the employer, contributions are pre-tax and can be used for eligible healthcare expenses. For 2026, the limit is $3,400 with a maximum carryover of $680. (Source)

Health Savings Accounts (HSA): Similar to FSAs, HSA contributions are deducted pre-tax and used to cover eligible medical expenses. For 2026, the HSA contribution limits are $4,400 for self-only coverage and $8,750 for family coverage. (Source)

These deductions benefit employees by reducing overall tax liability for both federal and territorial taxes.

Guam Tax Brackets in 2026

Guam follows the U.S. federal income tax brackets, which are applicable to the 2026 tax year. These tax brackets apply to individuals, married couples filing jointly, and heads of households. Below is a comprehensive list of the 2026 U.S. federal income tax brackets that Guam uses:

2026 Guam Tax Brackets (Individual Filers)

2026 Guam Tax Brackets (Married Filing Jointly)

2026 Guam Tax Brackets (Head of Household)

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These tax brackets reflect the same structure as the U.S. federal system, and Guam residents should file their taxes with the Guam Department of Revenue and Taxation.

2026 Guam Local Tax (Business Privilege Tax – BPT)

Guam imposes a local tax known as the Business Privilege Tax (BPT) — historically called the Gross Receipts Tax (GRT) — on businesses operating in Guam. Under Bill 44-38 (FY2026 Guam Budget, enacted via legislative veto override), the BPT rate is being phased down from the previous 5% rate:

Qualifying small businesses may apply a reduced BPT rate of 3% on the first $500,000 of aggregate gross proceeds from covered activities, if their aggregate gross annual income from all activities is at least $50,000 but not over $500,000 in the prior tax year. (Source)

The BPT applies to the gross revenue of businesses operating in Guam, regardless of profitability. Certain types of income may be exempt, including government contracts and wholesale transactions. All BPT returns must be filed electronically via guamtax.com — mandatory since February 2021.

Median Household Income in Guam

According to the U.S. Census Bureau’s 2020 Island Areas Census, the median household income in Guam was $58,289 in 2019. This reflects the territory’s economic conditions, which are influenced by factors such as government employment, the U.S. military presence, and tourism. (Source)

Note: Guam is not included in the annual American Community Survey (ACS) 1-year estimates produced for U.S. states. Income data is collected through the Island Areas Census, which is conducted every ten years.

Guam Tax Brackets 2026 Summary Table

Here is a summary table of the 2026 Guam Tax Brackets. Guam follows the U.S. federal tax rates, and the brackets mirror those set by the IRS for federal taxes:

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